The present invention relates to a method for updating map data of a navigation system and a system for updating map data of a navigation system.
Since the use of navigation systems in vehicles has been increasing for a long time, it has become increasingly necessary to update the map data, on the basis of which the navigation, the route search or the destination guidance is executed and which are stored in the navigation system, especially in older systems.
It is known to update the map data by exchanging for an appropriate exchange memory, such as a map data DVD (Digital Versatile Disc). This exchange is relatively expensive for the customer and the supplier, not case related, and is usually performed within the framework of relatively few versions per year, and hence, at relatively long time intervals.
Newer updating methods propose loading the data from a central server into the navigation system, for example, by means of a mobile radio system. Since for this purpose a large quantity of data is to be transmitted on a regular basis, this solution is associated with high costs and is quite time consuming for the user of the navigation system.
Against this background, an object of the invention is to provide a technical teaching, with which the map data of a navigation system can be updated in a convenient and economical way.
This object is achieved with the features disclosed in the independent claims. Advantageous further developments of the invention are disclosed in the dependent claims. At the same time further developments that are disclosed in the independent system-related claim and that correspond to the dependent method-related claims are also within the scope of the invention.
Hence, the invention is based on the core idea of maintaining not only the most recent version of the map data, but also older versions of the map data on a map server and to update the map data in a navigation system only if a map server-internal comparison between a first route, which was determined by the map server on the basis of an older version, which is also maintained in the navigation system, and a second route, which was determined by the map data on the basis of the updated version, results in a deviation—in particular, with respect to the route or the duration of the trip—that exceeds the threshold value.
The invention achieves this object in that the map data in the navigation system are not updated as a function of the version numbers or the defined time intervals, but rather the updating is need-based as a function of the specific utility of an update for the respective user of the navigation system.
Thus, for example, it is possible to suppress the updating of map data that relate to routes that are never driven by the user of the navigation system. In addition, it is possible to suppress an updating of map data that relate, for example, to an additional highway exit that the driver never takes, even though he routinely drives on the respective highway. In addition, it is possible to suppress an updating of map data that relate, for example, to the grading of a country road, but that has no influence or no significant influence on the driving time.
This case-dependent suppression of the transmission of map data, for example, by means of a mobile radio system, leads to a sizeable cost trimming (with respect to the transmission fees) and sharp decrease in the transmission time. Yet owing to the invention the user always receives automatically and transparently to him access to the map data, which has been updated with useful information for him, by means of the navigation system.
Several versions of the map data may be stored in the memory device of the map server. These versions comprise at least one version, which is stored in the navigation system, and a more recent version.
The driving destination may be entered by the user into the navigation system by means of an input device or automatically selected by the system itself or manually selected from a plurality of predetermined destinations.
The map data in the navigation system and in the map server do not have to be identical with respect to their regional coverage. However, they ought to overlap at least in one subarea.
The version of the map data that exists in the navigation system may be transferred with the driving destination to the map server; and on the basis of this version the first route may be determined in the map server.
The current position of the vehicle and/or the route criteria (fastest route, shortest route, . . . ) may be transmitted with the driving destination by the navigation system to the map server; and the map server determines the routes in consideration of these route criteria. The current position of the vehicle may also be determined by means of a satellite-based position determining system that is installed in the vehicle or may be inputted by the driver by means of an input device.
The degree of agreement between the first route and the second route may be determined on the basis of the duration of the trip, on the length of the route, on the fees that are incurred, etc. If the difference between the first and the second route with respect to one of these parameters exceeds a defined threshold value, then the second version of map data and/or route data that describe the second route is at least partially transmitted to the navigation system.
The transmission of the second version of map data and/or the route data that describe the second route may also be based on the transmission of the difference map data between the first and the second version. In this way the quantity of data to be transmitted can be reduced even more.
Map data may describe, according to the invention, any part or segment of map data—for example, relate only to certain regions, route segments or additional information, such as filling stations or points of interest.
Of course, the invention does not have to be executed every time a driving destination is selected, but rather may be executed, for example, only after permanently defined minimum time intervals, which may be determined on the basis of the destination.
According to one exemplary embodiment of the invention, several destinations are selected from a plurality of stored preferred favorite destinations, which follow automatically, for example, from a selection frequency in the past; and the respective appropriate destination data are transmitted to the map server. Then for each of these destinations the map server can determine, according to the invention, different routes from the map data on the basis of the different versions (e.g., first version and second version). As a function of the results from the respective comparison, an updating of the map data in the navigation system may or may not take place.
The aforementioned object is also achieved with a suitably configured system for updating the map data of a navigation system.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.